The invention relates to a device for sorting flat-area piece goods, such as packets, packages, letters, etc. The device has a drum cylinder open towards its outside at both faces, mounted at an angle to rotate on a bearing body. The mantle surface of the cylinder is structured with longitudinal rollers that rotate about their longitudinal axis, and arranged at a distance from one another, mounted on annular flanges.
Flat-area piece goods, such as packets, packages, and letters, must be sorted with reference to their destination, or town, to allow effective further handling or delivery. Postal codes, in particular, serve as a sorting parameter for packets, packages, letters, etc.
The piece goods arrive in the form of bulk goods, mixed up with one another and on top of one another, in all directions. These piece goods must consequently be sorted and separated by size, and also sorted, to determine the individual sorting parameter assigned to the piece goods, and to be able to sort the piece goods appropriately.
Sorting the piece goods by size is practical if broken up by thickness. These piece goods can be sorted by area, for example, the format or surface area of the piece goods, which preferably have rectangular surfaces.
To sort flat-area piece goods based on area or thickness, sorting devices have generally become known, wherein the piece goods must first be separated along a long sorting line, arranged one behind the other, using conveyor belts. Subsequently, the separated piece goods, conveyed in a line one behind the other, are branched off towards the side or towards the top using special and complicated grasping and/or transport mechanisms to sort them by thickness or by area. These sorting devices are complicated in their design, tend to break down, and have defects. In addition, these devices require a significant amount of set-up area, and throughput or sorting output.
A device for separating individual parts with different shapes and sizes by machine, particularly injection-molded parts, is known from German Patent DE 26 37 851 B1. This device consists of a drum cylinder that is open on both faces, mounted at a slant, so as to rotate. The mantle surface of this design is composed of longitudinal rods mounted in two lateral rings so as to rotate about their longitudinal axis. The rods are arranged at a distance from one another, wherein the rods are structured as mantle rollers that rotate counter to the rotation direction of the drum cylinder.
It is true that this device is practical for separating injection-molded parts into smaller and larger parts. However, it does not meet the special requirements that exist associated with sorting flat-area piece goods, particularly letters.
Only a low sorting output or a poor sorting quality can be achieved with this device for piece goods that easily slide on one another. This problem can be further reinforced due to undesirable catching or jamming of the flat-area piece goods in the mantle slits that can continue to occur, so that permanent disruptions of the sorting process can also occur.
Furthermore, drum devices for sorting flat-area piece goods have become generally known, which have a plurality of longitudinal plates at the mantle circumference. These plates are arranged at a certain incline angle relative to one another, leaving a mantle slit for the piece goods to be sorted out. Undesirable jamming of the flat-area piece goods can occur at the plate edges, in the region of the opening slits, with the possibility of significant damage to the goods.
Accordingly, it is a task of the invention to create a device which has a simple structure and with which large amounts of piece goods, particularly letters, can be sorted with a high sorting output and a low risk of damage.
The invention relates to a system that has longitudinal rollers that are arranged as steps that extend towards the inside, formed in each instance by a roller arrangement of longitudinal rollers.
The main point of this design is so that the roller mantle has longitudinal rollers that are offset towards the inside. Because of the steps that are formed as a result, the backward slippage of the piece goods that otherwise occur due to gravity when the cylinder is rotated about its longitudinal axis is reduced, and the piece goods are transported further upward within the drum. When this happens, the piece goods can be placed in a more upright position, so that it is easier for them to fall through the gap formed between the steps, such as the roller arrangements. As a result of these measures, which appear to be comparatively simple, the sorting output is clearly increased, without any damage to the flat-area piece goods occurring. Therefore, large amounts of piece goods can be effectively sorted within a short period of time.
The flat-area piece goods can be continuously fed to the drum cylinder, and the piece goods which can be rolled about in the drum can be separated with a high level of sorting quality. Constant sorting can be performed whereby a first part of the piece goods can fall down through the mantle slits, while a second part of piece goods with a greater thickness can be transported away, preferably through one of the face openings of the drum. Further transport of the piece goods within the rotating drum occurs in a simple manner, supported by the force of gravity, as a result of the drum""s slanted position in the longitudinal direction. Thus, in this manner, the piece goods are moved along upward a short distance within the drum mantle, during a rotation of the drum. The pieces then fall back, and slowly move in the direction of the drum""s longitudinal axis, in the direction of one of the face openings, in accordance with the slanted position of the drum cylinder, where the piece goods with a greater thickness can be transported away.
It is practical if every roller arrangement has the same number of longitudinal rollers, thereby resulting in an advantageous, uniformly good sorting output over the drum circumference.
It is furthermore practical if each of the roller arrangements comprise at least three longitudinal rollers. The outside circumference of these three roller is arranged in a common flat plane. In this way, there can be advantageous guide conditions for piece goods that essentially have small areas. Thus, the sorting output that is also further improved.
According to a practical further development, adjacent roller arrangements extend inward in the rotation direction of the drum cylinder, leaving a passage gap for the piece goods to be sorted out. In addition, adjacent roller arrangements can overlap inward, at least partially, forming a passage gap for the piece goods to be sorted out. With this design, at least one longitudinal roller of each roller arrangement, overlaps at least one longitudinal roller of a directly adjacent roller arrangement, towards the inside. As a result of the above measures, the sorting output and the sorting quality can be further increased.
At least one of the longitudinal rollers should be assigned to be a step, and can be put into rotation about its longitudinal axis via a drive. In this way, the sorting process can be influenced and supported in targeted manner, so that an even greater sorting output is possible.
A set of longitudinal rollers can be put into rotation about their longitudinal axes by the drive and can rotate about their longitudinal axes with the rotation direction of the drum cylinder in a first circumference region. In a second circumferential region, these longitudinal rollers can be put into rotation about their longitudinal axes opposite to the rotation direction of the drum cylinder. In this way, the sorting output can be further effectively increased, without any damage to the piece goods occurring and without any lasting disruption of the sorting process as the result of any wedging of the piece goods that might occur in the region of the passage slits.
In addition, the drive of the longitudinal rollers can comprise at least one auxiliary drive body, which can be brought into direct and/or indirect contact with the longitudinal rollers to be put into rotation about their longitudinal axes. This rotation is in such a way that a rotation of the drum cylinder in the rotation direction results in a rotation of the contacted longitudinal rollers. In this way, a particularly simple and robust design can be created, without any need for separate auxiliary drive units to drive the longitudinal rollers about their longitudinal axes.
It is also practical if the auxiliary drive body is structured as a press-down element that surrounds the outside longitudinal rollers at least partially in the circumference direction of the drum cylinder.
In addition, these auxiliaries are mounted on the annular flange so that it can be moved in the direction of the longitudinal rollers to be put into rotation about their longitudinal axes. In this case, the auxiliary drive body can be placed against them, so that the auxiliary rollers can come into contact with these longitudinal rollers. Using these auxiliary rollers, the longitudinal rollers can rotate in the opposite direction in a simple manner.
It is practical if the auxiliary drive body is structured as an elastic band, such as an elastic tension belt. Such a tension belt is simple and robust, and can be easily handled and replaced, if necessary.
In a particularly preferred exemplary embodiment, the invention relates to a device for sorting flat-area piece goods, particularly packets, packages, letters, and the like, with a drum cylinder open towards the outside at both faces, mounted at an angle so as to rotate on a bearing body. With this design, the mantle surface of the cylinder is structured with longitudinal rollers that rotate about their longitudinal axes, arranged at a distance from one another, and mounted on annular flanges. These longitudinal rollers can be put into rotation about their longitudinal axes via a drive, with the rotation direction of the drum cylinder in a first circumference region. In addition, these rollers can be put into rotation about their longitudinal axes opposite to the rotation direction of the drum cylinder in a second circumference region.
With this design, the sorting output can be effectively increased, without any damage occurring to the flat-area piece goods and without any lasting disruption of the sorting process as the result of any wedging of the piece goods that might occur in the region of the mantle slits. Even if any wedging of the piece goods were to occur in the bottom region of the drum cylinder, wherein the piece goods lie piled up due to the force of gravity, the jammed piece goods are taken along to the second circumference region. This movement occurs as the drum rotates further in the circumference direction, preferably in the upper part of the drum. These pieces are transported back to the interior of the drum, due to the longitudinal rollers that are put into rotation in the opposite direction, so that the plugged-up passage gap becomes open again.
In one embodiment of the invention, a first device and a second device are arranged in a cascade one after the other. If two such drums are set up one behind the other, a first sorting by thickness can take place in the first drum. Thus, it is practical if the passage gaps of the first drum cylinder are selected to be smaller than the passage gaps of the second cylinder. The gaps can be adjusted so that all of the piece goods that are less than 5 mm thick fall through in the first device. This result particularly relates to letters, especially standard letters. In the second drum device, those piece goods that have a thickness of 5 to 10 mm, can then be separated, such as with particularly compact letters. For piece goods with the greatest thickness, such as with a thickness greater than 10 mm, particularly large letters or maxi-letters, can be transported further within the second device and can also be sorted out according to this size class, to this extent.
An intake location for the piece goods of the second device should be arranged below a transfer location of the first device, so that the piece goods that remain at the first device can get from the transfer location of the first device to the intake location of the second device under the force of gravity. It is understood that driven transport devices, particularly conveyor belts, can also be used to transport between the devices arranged in a cascade. As a result of the above measures, the sorting accuracy can be further increased, and result in more effective sorting into several sorting sizes. In other words, there can be almost one hundred percent sorting of the flat-area piece goods by their thickness with such a cascade arrangement of several devices.
It is understood that the distances between the passage gaps for the piece goods can be adjusted differently from one device to another, so that only the thinnest piece goods, or those piece goods in the thinnest size group, are sorted out in the first device. Thus, other sized piece goods that are remaining that can be sorted out in subsequent devices. It is also possible that in the first device, all the piece goods except for those with the greatest thickness can be sorted out, so that the passage gaps are selected to be the largest. In addition, with the subsequent sorting devices with a smaller gap width, these sorting devices sort the piece goods that remain after the first sorting process, in other words those with a smaller thickness.
In the end result, the device can achieve almost one hundred percent sorting of flat-area piece goods that have different thicknesses, into several thickness groups using such cascade arrangements.
It is particularly advantageous if a device for sorting flat-area goods, such as packets, packages, letters, according to their area, is arranged upstream or downstream with reference to a transport direction of the drum cylinder. In this manner, perfect and complete sorting of the flat-area piece goods, particularly of letters, is possible both according to their thickness and according to their area size, in a preferably continuous process, at high sorting output and a high level of sorting quality, without subjecting the piece goods to relevant damage.